1. Field of the Invention
The present invention relates to a honeycomb structure, a method for producing the same, and an exhaust emission purification apparatus.
2. Description of the Related Art
As a method for producing a honeycomb structure that purifies (converts) exhaust emissions, various methods have been proposed in the past. For example, PCT Publication No. WO 02/020154A describes a method in which, a cordierite honeycomb carrier is first immersed in an alumina sol, followed by drying and firing, and the resulting product is wash-coated with a slurry for NOx occlusion catalyst wash-coating, followed by drying and firing to give a NOx occlusion catalyst. In the NOx occlusion catalyst, an alumina layer formed between an alkali element and the honeycomb carrier prevents the alkali element from eroding the honeycomb carrier. The contents of WO 02/020154A are incorporated herein by reference.